The present invention relates to thin-walled plastic containers which are provided with axially elongated accordion pleats in and about their sidewalls whereby to provide for the radial expansion and contraction of the containers. Commercially successful apparatus for providing the accordion pleats in the sidewalls of the containers has been unavailable to the present time.
It is the general object of the present invention to provide apparatus for forming a circumaxially extending series of axially elongated accordion pleats in and about the sidewall of a generally cylindrical thin-walled plastic container, which apparatus may be operated cyclically whereby to accommodate a succession of containers in an efficient high speed production operation at economic advantage.